(i) Field of the Invention
This invention relates to a mat for collecting debris such as leaves and sticks, from a surface, such as the surface of a tennis court.
(ii) Prior Art
Outside playing courts, such as tennis courts, are often prone to accumulating leaves or other debris on their surface which must be periodically removed.
Australian patent 628556 describes a mat for sweeping a surface, the mat comprising slots through which debris, such as leaves or sticks, can pass to collect on the upper surface of the mat.
The mat may be composed of a semi-flexible material, such as rubber or a suitable polymeric material.
The slots may be elongate with the longitudinal axis of each slot facing genially in the direction of travel of the mat. The trailing edge of each slot may be chamfered to lift debris onto the upper surface of the mat. The trailing edge of each slot may face perpendicularly to the direction of travel or may be inclined, for example at 45xc2x0. In the mat, all of the slots may be inclined to the direction of travel, or some may be inclined with others being perpendicular to the direction of travel.
In one particularly advantageous form, the mat is of a grid-like construction for xe2x80x9cbaggingxe2x80x9d a clay tennis court, with portions of the grid being removed to define the slots. Thus xe2x80x9cbaggingxe2x80x9d of the court periodically during play will also serve to remove leaves and other debris from the surface of the court.
In a particular form, the mat is of grid-like construction, presenting an array of apertures, typically of rectangular form, and about 12.5 mm side dimension, arranged with sides at about 45xc2x0 to the intended direction of travel of the mat.
Arrangements as above described have been found particularly useful for, among other things, sweeping debris from tennis courts. It has now been found that by forming the unslotted part of the mat in a particular way, improved operation is achieved when cleaning certain court surfaces.
In one aspect, the invention provides a mat for sweeping a surface, the mat having slots through which debris can pass to collect on the upper surface of the mat, as the mat is passed over a surface to be swept, the mat being formed as a perforate structure having an array of first apertures therethrough, and within at least a substantial proportion the first apertures, mesh structures which, within the respective first aperture, present a respective array of second apertures of substantially smaller size than the first apertures.
The first apertures may for example be about 150 mm in area, and the second apertures may be in the range 2.25 to 25 mm2, such as 9 or 10 mm2. The first apertures may be formed by a grid-like structure having, for example, intersecting sets of parallel walls which cross at an angle, such as 45xc2x0. The first apertures may then be rectangular, such as square. The second apertures may be similarly formed, the mesh structures defining opposed sets of transversely disposed elements extending between opposed walls of the respective first aperture. These elements forming the mesh structure may conveniently extend parallel to opposed ones of the walls defining the first apertures.
Preferably, the elements defining the second apertures are disposed at locations at or towards the bottom edges of the walls. By this, the walls extend upwardly around the second apertures in each first aperture.
Preferably, too, the second apertures are present in a substantial portion at least, preferably all, of the first apertures spaced away from the trailing edges of at least a substantial proportion of, preferably all, the slots, and not present in at least a substantial proportion, preferably all, of the first apertures adjacent the trailing edges of the slots.